Hydraulically operable rotary crane



June 5, 1962 F. POHL 3,037,642

HYDRAULICALLY OPERABLE ROTARY CRANE Filed June 5, 1959 INVENTOZ United States Patent Office 3,037,642 Patented June 5, 1962 3,037,642 HYDRAULICALLY OPERABLE ROTARY CRANE Friedrich Pohl, Hamburg, Germany, assignor to Hydrostahlbau-Gesellschaft Wiese & Co., Hamburg, Germany Filed June 5, 1959, Ser. No. 818,460 Claims priority, application Germany June 13, 1958 4 Claims. (Cl. 212-69) The present invention relates to hydraulically operable rotary cranes in which a platform forms the base for the crane superstructure, the so-called crane column, which carries the mechanical equipment for the crane and has pivotally connected thereto the overhang beam and the parts associated therewith.

More specifically, the present invention concerns the arrangement of the fluid reservoir for the actuating fluid or actuating oil employed for the hydraulic drive of the crane.

It is an object of the present invention to provide a hydraulically operable rotary crane with a container for the actuating fluid in such a way that a minimum space of the crane proper will be taken up thereby, even though the capacity of said fluid reservoir may be at least as great or even greater than the fluid reservoir for correspondingly sized cranes.

It is another object of this invention to provide a hydraulically operable rotary crane with a fluid reservoir for the actuating fluid employed in the crane, which will favorably affect the center of gravity of the crane and reduce the tilting torque thereof.

These and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawing, in which:

FIG. 1 represents a perspective view of the crane column with the fluid reservoir according to the present invention.

FIG. 2 is a perspective view partly broken away of the crane base according to the present invention.

According to the present invention, the crane platform is designed as a closed box-1ike fluid reservoir for the actuating fluid of the hydraulic drive of the crane. Such an arrangement has the advantage that the center of gravity of the entire crane is considerably lower than similar heretofore known cranes, while the tilting torque is considerably reduced. In addition thereto, the arrangement of the present invention makes it possible to increase the volume of the container by a multiple over the heretofore known fluid reservoirs which are located at a relatively high point of the crane column and therefore are limited as to their capacity. On the other hand, the arrangement according to the present invention economically makes use of the relatively considerable height which the platform has anyhow.

Due to the fact that the fluid reservoir according to the present invention has a considerably greater capacity than the fluid reservoirs heretofore customary in connection with rotary cranes of the type involved, a correspondingly greater quantity of fluid will be circulated which inherently has a greater heat absorption capacity, thereby resulting in an improved cooling of the fluid. It should also be noted that in view of its location the fluid reservoir with the exception of its side Walls is protected against the sun, which fact is of particular importance in tropical areas and will always assure safety of operation.

Passage 12 is also availed of for receiving electric wires or cables leading to the motor of an electrically driven hydraulic pump unit which is diagrammatically shown in dot-dash outline in FIGURE 2 and generally designated by reference numeral 7.

Referring now to the drawing in detail, the structure shown therein illustrates the crane colmn generally designated 1 which is composed of a truncated pyramid frus trum and a prism-shaped portion and is provided with ears 2 for receiving the heating means for the pulleys or sheaves for the cable work. The crane column 1 is furthermore provided with studs 3 for the overhang beam. In addition thereto, the crane column is equipped with an operators seat 4.

As will be evident from FIG. 1, the crane column rests on a platform 5 which in its turn is supported by a ball bearing supported turntable 6 for the rotational movement of the crane. The platform 5 which supports the crane column is generally a box-like structure with a continuous bottom wall and side walls so as to form a fluid tight container or reservoir for the hydraulic fluid for the operation of the crane. The particular hydraulic circuit is not illustrated in the drawings.

The box-like base has a cover plate on top which may be a part of the base or which may be the bottom plate of the column which rests on the base.

The interior of the base 5 is divided into compartments by a plurality of partitions 10 having apertures 11 therein, so that the compartments will be in fluid communication with each other.

Two suction conduits 3 lead downwardly into the base 5 for withdrawing fluid therefrom and a return conduit 9 leads into the base at a point spaced from both of the conduits 8 so that the fluid returned to the base admixes with the other fluid therein and has an opportunity to lose its heat before it is again picked up by the suction conduits.

The partitions 10 serve as stiffening members so that the weight of the column is adequately supported.

In about the middle of the base 5 and on the axis of rotation thereof, there is a cylindrical member which forms a passage 12 which extends through base 5 which is isolated from the fluid compartment so that the electrical conductors and the drive mechanism for the crane can pass therethrough.

As will be evident from the drawing, the capacity of the platform or box-shaped container 5, obtained primarily by the height of the platform, represents a considerableportion of the volume of the entire crane column, which fact together with the low position of the fluid reservoir brings about the above mentioned advantages. The favorable cooling effect upon the operating fluid is aided by the fact that the suction and return conduit connections 8 and 9 are relatively far spaced from each other so that a highly satisfactory temperature equalization will be effected in the reservoir between the returning and the drawn-out fluid.

It is, of course, to be understood that the present invention is, by no means, limited to the particular construction shown in the drawing but also comprises any modifications within the scope of the appended claims.

What I claim is:

1. In a crane column construction: a rotatable base, a crane column above said base, and a platform supported by said base and engaged by the foot portion of said column, said platform forming a normally closed boxshaped container for receiving and storing the operating fluid for use in connection with the hydraulic operation of an overhang beam in connection with which said crane column construction is to be used and directly supporting said column.

2. In a crane column construction: a rotatable base, a crane column above said base, and a platform supported by said base and engaged by the foot portion of said column, said platform forming a normally closed boxshaped container for receiving and storing the opera-ting fluid for use in connection with the hydraulic operation of an overhang beam in connection with which said crane column construction is to be used, said platform being provided with passage means thereby permitting the passage of a rotary mechanism and current conducting means through said passage for an electric pump drive of a hydraulic circuit in connection with which said crane column construction is to be used, said platform supporting said column.

3. In a crane column construction: a rotatable base, a crane column above said base, a platform supported by said base and engaged by the foot portion of said column, said platform forming a normally closed box-shaped container for receiving and storing the operating fluid for use in connection with the hydraulic operation of an overhang beam in connection with which said crane column construction is to be used, and partitions arranged in said box-shaped container for stiffening the latter, said partitions being provided with apertures for establishing free intercommunication between the compartments formed by said partitions, said platform bearing the entire weight of said column.

4. In a crane column construction: a rotatable base,

a crane column above said base, and a platform supported by said base and engaged by the foot portion of said column, said platform forming a normally closed boxshapcd container for receiving and storing the operating fluid for use in connection with the hydraulic operation of an overhang beam in connection with which said crane column construction is to be used, said box-shaped container being provided with inlet and outlet openings spaced from each other by a relatively great distance for connection with hydraulic conduit means and vertical apertured partition walls in said platform to impose strength thereto, said platform supporting the entire weight of said column.

References Cited in the file of this patent UNITED STATES PATENTS 1,273,618 Julien July-23, 1918 2,365,168 Billings Dec. 19, 1944 2,479,838 Huston Aug. 23, 1949 2,815,703 Talak Dec. 10, 1957 

